Abstract

Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline. The aim of the study was to establish the state of the species at selected sites in the west Swedish agricultural landscape and to describe the surrounding environment and its possible effects on the study species and its decline. The survey was carried out during three weeks in September and November 2005, at 29 former known localities. The localities were situated in the province of Västergötland. The species was relocated at only two localities. These sites were open grazed land, not changed since the last time B. bicolor was seen. Half of all of the localities were more or less grown over. Most likely there are several causes of the decline of the species and one of them is the modern way to manage the land. One consequense of this is the overgrown landscape.To some part, the air pollution has decreased during the recent years, but it might still be too high for B. bicolor. Changes in temperature and weather; the climat change, can also have an impact on the situation for the lichen. On one of the localities snails had grazed on the lichen. This is interesting and more studies around this are welcome to be made.